Antimicrobial Resistance in Pediatric UTIs with Congenital Urogenital Anomalies: An 11-Year Saudi Retrospective Study

Background/Objectives: Children with congenital urogenital anomalies (CUA) face increased risk of urinary tract infections (UTIs) and may harbor resistant organisms due to recurrent infections and antibiotic exposure. This study characterized the distribution of uropathogens and antimicrobial resistance patterns at a tertiary center in Saudi Arabia. Methods: This retrospective cohort study included pediatric patients (<18 years) with documented congenital urogenital anomalies and positive urine cultures at King Khalid University Hospital, Riyadh (2015–2025). Susceptibility interpretations (S/I/R) were extracted from the hospital laboratory information system; multidrug resistance (MDR) was defined using organism-specific Magiorakos criteria. Results: A total of 168 patients (72.0% male; mean age 4.1 ± 4.5 years) contributed 411 UTI episodes. Among 403 mono-organism episodes (after excluding eight polymicrobial cultures), Escherichia coli predominated (150/403, 37.2%), followed by Klebsiella pneumoniae (96/403, 23.8%) and Pseudomonas aeruginosa (33/403, 8.2%). High resistance was observed for ampicillin (83.6%), trimethoprim-sulfamethoxazole (54.2%), and cephalosporins (cefazolin 62.8%, cefotaxime 35.6%). Carbapenems (2.9%) and aminoglycosides (9.2%) retained >90% susceptibility. Overall MDR was 35.5%, highest among Klebsiella oxytoca (57.1%) and Escherichia coli (47.6%). Recurrent infections showed numerically higher unadjusted resistance than single episodes. Conclusions: Pediatric patients with congenital urogenital anomalies showed high first-line antibiotic resistance. Carbapenems and aminoglycosides retained predominantly susceptible in vitro profiles in this cohort and may inform empiric considerations alongside ongoing local susceptibility surveillance for this high-risk population.